In general, it is possible to grasp the stock status in a store by cooperation with a Point of Sales (POS) system. However, it is difficult to grasp the presence or absence of commodities on commodity display shelf, and even hot-selling commodities are sometimes out of stock on the commodity display shelf, which causes sales opportunity losses. Further, although it is known that the sales clearly vary depending on the way commodities are arranged in the commodity display shelf, it takes time for a store clerk to check the arrangement of commodities on the commodity display shelf one by one, and thus the commodities are sometimes left uncontrolled without being appropriately arranged for enhancing the sales of the commodities. Therefore, there is a need for a technique of quickly managing the display state of commodities.
Patent Literatures 1 and 2 below are known as techniques related to the management of articles such as commodities. Patent Literatures 1 and 2 disclose an article management method that places an RFID tag at a commodity display position on a shelf, and determines that there is a commodity when the RFID tag cannot be read by an RFID reader.